DE 2431937 A1 in the name of Sennheiser Electronic KG describes the use of multi-channel infrared transmission of audio feeds in different languages from interpreters at a conference to receivers in headsets worn by conference delegates.
International standard IEC 61603-7, entitled “Transmission systems of audio and/or video and related signals using infra-red radiation—Part 7: Digital audio signals for conference and similar applications”, describes the characteristics of a digital multiple channel, multiple carrier audio transmission system as an extension to conference interpretation or similar systems using the frequency ranges 45 kHz to 1 MHz and 2 MHz to 6 MHz.
Known systems include a signal generator, sometimes referred to as the transmitter, which provides a modulated signal to one or more radiators. The radiators transmit the signals supplied by the signal generator as an optical signal, in particular in the form of infrared radiation. In order to cover large spaces with an adequate infrared signal, multiple radiators have to be used. Radiators are typically connected to the signal generator in a daisy-chained configuration.
It is a disadvantage of the known systems that, when multiple radiators are used, these radiators must be manually configured to introduce an artificial delay so as to synchronize the infrared signal of the different radiators, with different positions in the daisy-chain. Manual configuration of a radiator requires access to the radiator's control panel, which is difficult to reach once the radiator is mounted in its operational position (usually at great height on a wall).
It is a purpose of embodiments of the present invention to at least partially avoid this disadvantage.